6 bright orange/red light orbs seen North/East from Boulder in sky over Niwot/Longmont. Orbs were "stacked" and "staggered" over each other with 2 lights above, then down and left, 2 more lights and then down and left, the last two lights:

* * * * * *

Orbs remained motionless in sky and then faded away like dying embers.

My first impression was airplane headlight but Orb colors never changed to white. And, most planes approaching DIA for landing do so further out east over the plains.

Very strange. Maybe fire balls as some have mentioned. Maybe they were Chinese lanterns. That would kind of make sense but they did appear brighter and higher than a typical Chinese lantern would float to.